Improved rotary engine



UNITED y STATES PATENT OFFICE.

JOHN B. ROOT, OF BATTLE CREEK, MICHIGAN.

IMPROVED ROTARY ENGINE.

Specification forming part of Letters Patent No. 34,3?6, dated February11, 1862.

' I do hereby declare that the following is a full,

clear, and exact description of the same, reference being had to theaccompanying drawings, forming part of this specication, in which-Figure I is a vertical section in a plane parallel with the plane ofrevolution, of an engine with my improvements. Fig. 2 is an a-Xialsection of the same. Fig. 3 exhibits a face View of one of the pistonsand section of its eccentric bands.

Similar letters of reference indicate corresponding parts in the severaliigures.

This invention relates to that description of rotary engine Whose innerrotating drum, to which the pistons are attached, is arrangedeccentrically within the stationary cylinder.

It consists in certain improved means of keeping the pistons out incontact with the inner periphery of the cylinder and radial to thecenter thereof in their revolution with the eccentric drum.

It also consists in an improved construction of and mode of applying andsecuring the cylinder-heads to the cylinder, whereby the pistons areprevented from binding in case of unequal expansion of the cylinder.

It also consists in a certain arrangement of a valve and stop, incombination with a steamjacket round the cylinder to provide for thewarming up and expansion of the cylinder before starting the engine,aswell as for keeping the cylinder warm during the operation of thecylinder; and it further consists in a certain arrangement ofexhaust-valves used in connection with such jacket to provide for thereversal of the engine.

To enable others skilled in the art to make and use my invention, I willproceed to describe its construction and operation.

A is the cylinder bored truly and fitted at each end with a movable headB.

C is the rotating drum to which the pistons are'attached, said drumbeing of cylindrical form and being secured iirmly to the main shaft D,which is arranged to work in bearings in the cylinder-heads, theposition of such bearings being so much eccentric to the cylinder A thatthe drum C may work in contact with a packing-piece or stationaryabutment E, which is fitted to a cavity formed for its reception in theinner periphery of the main cylinder.

F F are the pistons fitted to the drum C with cylindrical segment-piecesd d, as described in my last Letters Patent, and having each iirinlysecured to it two rings ci ct, fitted with cylindrical linings b I),which are fitted to two cylindrical hubs c c, projecting inward from thecylinder-heads, one lining b serving for both or all the rings fitted toone hub. The hubs c c are eccentric to the shaft D and drum C, butconcentric with the inner periphery of the cylinder, and consequentlykeep the pistons radial to the center of the cylinder and in contactwith its inner periphery. The cylindrical linings b Z) can be taken outand replaced by new ones Whenever it becomes necessary by their wear orthe Wear of the hubs c c or rings ct a. The said linings are of greatimportance apart from their taking the wear, as by placing them in therings before inserting the piston-drum in the cylinder the ringsbelonging to either hub are all kept opposite each other and enabled tobe all put on or to receive their respective hubs without difficulty,whereas Without them it would be very difficult to get the rings all onthe hubs. The pistons F F and their rings c c may be of cast-iron andthe linings b b of brass or composition metal. The hubs c c may be caston the cylinder-heads, which will be of cast-iron. The piston-drum C ishollowed out on each side, as shown at e e in Figs. 1 and 2, for thereception of the hubs c c and rings (t a. The hubs c c and rings a aconstitute a most effective means of keeping the pistons radial to andin contact with the inner periphery of the cylinder A, as besides havingthe greatest degree of stability and durability they provide for a veryeasy movement. The number of pist-ons that may be employed is notlimited to two, but three, four, or more may be used.

The two cylinder-heads B B, instead of being rigidly secured to thecylinder in the manner common to rotary engines, vhave their peripheriesturned to iit the interiorof the cylinder A and are grooved and fittedwith packing to keep them steam-tight therein, and they have deeprabbets f 1I f z' in the outer sides to enable them to be secured intheir places by means of two rings G G, (see Fig. 2), which are boltedone to each end of the cylinder, the said rings having rabbets g j g jturned in their outer sides to correspond with the rebates fz' fi andform continuations of the bore of the cylinder for the reception ofportions of the packed peripheries of the cylinder-heads, and theopenings h h of the said rings heilig large enough for the reception ofthe cylindrical portions t' 7l of the rebates in the heads. One of therings G G may be secured to the cylinder and the corresponding head putin from the inside of the cylinder before the piston-drum is put in; butthe other one cannot be putin until after the piston-drum, and its ringG cannot be put on the cylinder till after it has been placed therein.As a substitute for one of the rings, an inner flange may be providedaround the interior of one end of the cylinder, such flangecorresponding with the part j h of the ring. The pressure of the steamwithin the cylinder tends to force the heads outward, and this pressureis to be met and the wear compensated for by set-screws screwed throughthe portionj h, orby steam admitted between the rabbets f t' and gj.This mode of fitting the cylinder-heads allows them to adapt oraccommodate themselves to any unequal eX- pansion of the cylinder andkeep the shaft in the center thereof.

H H is the steam-jacket, which nearly surrounds the cylinder,terminating near opposite sides of the abutment E and being divided by atransverse partition copposite the abutment. The cylinder-ports l l',arranged on opposite sides of the abutment, communicate directly withthe cylinder and also with the jacket, as shown in Fig. l, and the saidports are to be covered by asteam-chest fitted with avalve similar t0what has been used in many rotary engines for the purpose of causing theinduction into either one and eduction from the other port, according tothe desired direction of the rotation of the shaft.

The two portions H and H on opposite sides of the partition 7c areconnected by two small passages m m with the seat of a cock or valve I,by which communication between them may be opened and closed, and fromthe said porlions of the jacket there are two ports n n leading directlyinto the cylinder, such passages being at such equal distances from thepartition 7c that when one piston is passing one port another piston ispassing the other port; and these ports are fitted with valves p 29',which can be opened or closed from outside the cylinder and jacket byscrews or other convenient means. In the operation of the engine thevalve p or p on the opposite Side of the cylinder to that on which steamenters is always open, the object of such valves being to permit thesteam to be eX- hausted in such manner as to permit its being used to acertain extent expansively and to prevent any back-pressure on thepistons. Fig. l shows the induction taking place through the port Z andthe eduction through the port n of the valve p. The valve p is closed topermit the expansive force of the steam left within the cylinder betweena piston that has passed the port l and another which has not yetarrived at n to act upon the latter piston. When it is not desired touse the steam expansively, both valves p and p may be open.

The valve I is always closed while the engine is in operation, and theportion of the jacket on the induction side of the partition cis alwaysfilled with live steam and the portion on the opposite side with theexhausting steam, and

hence the cylinder is kept warm. To provide for the warming of thecylinder before starting the engine, and thereby causing it to expandbefore the working parts and so preventing the binding of the latter,the valve I is brought to a position to admit steam through the passagesm m', and so make communication between the two compartments I-I H ofthe steam-jacket, and on either port Zor Z being opened to the steamchest the whole jacket is filled with live steam. Vhen the cylinder hasbeen warmed in this way, the engine is started by merely closing thevalve I.

What I claim as my invention, and desire to secure by Letters Patent,is-

1. The combination of the rings d a, attached to the pistons, and thehubs C C, projecting inward from the cylinder-heads in positionseccentric to the shaft and pistondrum, but concentric with the cylinder,substantially as herein specified.

2. The cylinder-heads B B, constructed with rabbets and fitted to thecylinder and to rabbets in rings G G, or flanges secured to or formed onor in the cylinder, substantially as and for the purpose hereindescribed.

3. The steam jacket H H with its two compartments communicating with thecylinder-ports Z Z', its partition lo, passages m m, and valve I, allconstructed and arranged and operating substantially as herein setforth.

4. The two ports n n and valves p p', combined with the cylinder andsteam-jacket H H', substantially as and for the purpose hereindescribed.

5. The linings b b, applied in combination with the rings@ dof thepistons and the hubs c c of the cy linder-heads, substantially as andfor the purpose herein specified.

JOHN B. ROOT.

Witnesses:

LoUIs A. TUCKER, M. M. LIVINGSTON.

